Half-metallic ferromagnetism in Ag-doped ZnO: An ab initio study

The spin-resolved electronic structures of ZnO doped with 6.25% Ag have been studied with the first-principles calculations based on the spin density functional theory. The substitutional Ag impurities and their nearest neighbor O atoms are shown to be in a spin polarized state with a global magnetization of 1.0 mu(B) Ag-doped ZnO is in a ferromagnetic ground state which can be explained by Zener's double exchange mechanism. Furthermore, band structure calculations show a half-metallic behavior of the Ag-doped ZnO. These results indicate that Ag-doped ZnO shows promise as a dilute magnetic semiconductor free of magnetic precipitation and may find applications in the field of spintronics. (C) 2012 Elsevier Masson SAS. All rights reserved.